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The cobalt oxide-vanadium oxide (Co3O4-V2O5) combined with reduced graphene oxide (rGO) having band gap of ∼ 3.3 eV appeared as a suitable photocatalyst for selective oxidation of 2-naphthol to BINOL. C2-symmetric BINOL was achieved with good yield using hydrogen peroxide as the oxidant under UV-light irradiation. The same catalyst was chirally modified with cinchonidine and a newly synthesized chiral Schiff base ligand having a sigma-hole center. The strong interaction of the chiral modifiers with the cobalt-vanadium oxide was truly evident from various spectroscopic studies and DFT calculations. The chirally modified mixed metal oxide transformed the oxidative C C coupling reaction with high enantioselectivity. High enantiomeric excess upto 92 % of R-BINOL was obtained in acetonitrile solvent and hydrogen peroxide as the oxidant. A significant achievement was the formation of S-BINOL in the case of the cinchonidine modified catalyst and R-BINOL with the Schiff base ligand anchored chiral catalyst. The UV-light induced catalytic reaction was found to involve hydroxyl radical as the active reactive species. The spin trapping ESR and fluorescence experiment provided relevant evidence for the formation of such species through photodecomposition of hydrogen peroxide on the catalyst surface. The chiral induction to the resultant product was found to induce through supramolecular interaction like O H…π, H…Br interaction. The presence of sigma hole center was believed to play significant role in naphtholate ion recognition during the catalytic cycle.

We report investigations on the anticancer activity of organometallic [MII/III (η6 -p-cymene/η5 -pentamethylcyclopentadienyl)] (M=Ru, Os, Rh, and Ir) complexes of N-heterocyclic carbenes (NHCs) substituted with a triazolyl moiety. Depending on the precursors, the NHC ligands displayed either mono- or bidentate coordination via the NHC carbon atom or as N,C-donors. The metal complexes were investigated for their stability in aqueous solution, with the interpretation supported by density functional theory calculations, and reactivity to biomolecules. In vitro cytotoxicity studies suggested that the nature of both the metal center and the lipophilicity of the ligand determine the biological properties of this class of compounds. The IrIII complex 5 d bearing a benzimidazole-derived ligand was the most cytotoxic with an IC50 value of 10 μM against NCI-H460 non-small cell lung carcinoma cells. Cell uptake and distribution studies using X-ray fluorescence microscopy revealed localization of 5 d in the cytoplasm of cancer cells.

Functional imaging using fluorescent indicators has revolutionized biology, but additional sensor scaffolds are needed to access properties such as bright, far-red emission. Here, we introduce a new platform for 'chemigenetic' fluorescent indicators, utilizing the self-labeling HaloTag protein conjugated to environmentally sensitive synthetic fluorophores. We solve a crystal structure of HaloTag bound to a rhodamine dye ligand to guide engineering efforts to modulate the dye environment. We show that fusion of HaloTag with protein sensor domains that undergo conformational changes near the bound dye results in large and rapid changes in fluorescence output. This generalizable approach affords bright, far-red calcium and voltage sensors with highly tunable photophysical and chemical properties, which can reliably detect single action potentials in cultured neurons.

Global temperature has risen >1 °C since the preindustrial era, resulting in well-documented adverse climate impacts including extreme weather (floods, droughts, storms, and heat waves), a rise in ...

Catalytic partial oxidation of methane to produce syngas were studied over calcined hydrotalcites of varying Mg/Al ratios supported Rh catalysts. Hydrotalcites of varying Mg/Al ratios were prepared using their hydroxide precursors and intercalating them with amino acid lysine. Upon calcination, these hydrotalcites converted into their mixed metal oxides having mesoporosity and used directly as support materials for the synthesis of rhodium catalysts. Rh dispersion, size of the nanoparticles, and metal-support interactions were found to strongly influence the activity of the catalyst and their stability. Feed composition, gas hourly space velocity, and temperature were found to influence the catalyst activity, CO/H2 ratio, and CO/CO2 selectivity. Alumina and alumina-rich calcined hydrotalcites exhibit higher catalytic activity, but carbon formation and aggregation were prominent. In contrast, MgO and MgO-rich calcined hydrotalcite supported Rh catalysts exhibit moderate activity; however, they were resistant against particle sintering and carbon formation. Long-term testings of these catalysts were carried out, and it was observed that calcined hydrotalcites of varying Mg/Al ratios supported Rh catalysts were promising candidates as stable and active catalysts toward catalytic partial oxidation of methane.

Catalytic dry reforming of methane using carbon dioxide (DRM) to produce CO rich syngas (synthesis gas) over supported nickel catalysts presents major challenges including the carbon deposition and...

The goal of the present study is to treat industrial wastewater containing sodium aluminate using a chemically inert polyurea (PU) based thin film composite (TFC) reverse osmosis (RO) membrane to promote water reclamation and zero liquid discharge (ZLD). Pretreatment was carried out to reduce the pH of the effluent from 12.5 to 7.1. The TFC RO membrane was fabricated by coating PU on Polyethersulfone (PES) substrate by interfacial polymerization (IP). The surface and cross-sectional morphologies of the membrane were characterized using scanning electron microscopy (SEM). The indigenously synthesized membrane was effective in the removal of total dissolved solids (TDS), chemical oxygen demand (COD), colour and electrical conductivity. The experiments were conducted by varying the feed composition of the wastewater. The maximum water recovery and flux were found to be 74% and 73.9 L/m2·h. RO process using PU membrane exhibited significant potential for cost effective, safe and pollution-free treatment of sodium aluminate industrial effluent.

Liquid–liquid extraction of volatile fatty acids (VFA) from landfill leachate (LL) as well as synthetic solution (SS) whose concentration varied from 0.2 to 1 mol/L was investigated. The impact of extractant and feed VFA concentration on extraction efficiency (EE), distribution ratio (KD) and loading ratio (z) with the help of statistical analysis and process optimization using response surface methodology is presented. Physical extraction of VFA from SS using seven different diluents was performed to choose the best diluent. Reactive extraction of VFA was investigated with 10–50% (v/v) trioctylamine (TOA) and tributylphosphate (TBP) as extractants in 1-Octanol. Reactive extraction of VFA results disclosed enhancement of EE due to the synergistic chemical interactions between extractant and diluent. Majority of the acid extractant complexes formed were 1:1 with TBP while 1:1, 2:1 and 3:1 with TOA as verified by z > 0.5 The optimal extractant concentration for TOA and TBP was found to be 37.8% and 39.09% at a feed concentration of 0.67 mol/L and 0.81 mol/L for SS respectively to achieve maximum EE of 91% while it was 29.3% and 36.2% at 0.2 mol/L for LL to achieve EE of 52% and 57% correspondingly.

Herein, we report the synthesis of carbon-supported palladium–nickel electrocatalysts (ECs) (Pd4–xNix/C ECs, x = 1–3) as an important class of non-platinum ECs, for both oxygen reduction reaction (...

Significance Autophagy (cellular self-eating) is essential for the health and survival of eukaryotic cells. Therapeutic autophagy induction is a major goal in the field. Rubicon inhibits autophagy and is a potential target for autophagy inducers. Rubicon is localized to its site of action in the cell by binding to the small GTPase Rab7. Here, we report a high-resolution structure of a large part of Rubicon, known as the Rubicon Homology (RH) domain. We show how the RH domain binds to Rab7 and show that the Rab7-binding residues of Rubicon are essential for Rubicon localization and autophagy inhibition. This provides a roadmap to block Rubicon localization and activity in order to upregulate autophagy., Rubicon is a potent negative regulator of autophagy and a potential target for autophagy-inducing therapeutics. Rubicon-mediated inhibition of autophagy requires the interaction of the C-terminal Rubicon homology (RH) domain of Rubicon with Rab7–GTP. Here we report the 2.8-Å crystal structure of the Rubicon RH domain in complex with Rab7–GTP. Our structure reveals a fold for the RH domain built around four zinc clusters. The switch regions of Rab7 insert into pockets on the surface of the RH domain in a mode that is distinct from those of other Rab–effector complexes. Rubicon residues at the dimer interface are required for Rubicon and Rab7 to colocalize in living cells. Mutation of Rubicon RH residues in the Rab7-binding site restores efficient autophagic flux in the presence of overexpressed Rubicon, validating the Rubicon RH domain as a promising therapeutic target.

Shape-controlled metal nanomaterials are considered as a unique class of catalysts because of their synergistic size- and shape-dependent catalytic properties. This work reports the synthesis of a novel size- and shape-controlled catalyst, consisting of highly dispersed MnOx nanoparticles (average particle size of 4.5 nm) on shape-controlled SiO2 nanospheres (250–300 nm) for selective cyclohexene oxidation using air as the oxidant under solvent- and base-free conditions. The MnOx/SiO2 catalyst exhibited an excellent cyclohexene conversion (~ 92%) with a high selectivity (~ 96%) to the allylic products (2-cyclohexene-ol and 2-cyclohexene-one) under mild conditions, outperforming various SiO2 supported CoOx, FeOx, and CuOx catalysts. The better performance of shape-controlled MnOx/SiO2 nanocatalyst is due to high redox nature of Mn, uniform dispersion of smaller sized MnOx nanoparticles, and synergetic interaction between MnOx and SiO2 spheres, as evidenced by XPS and TEM studies. Further, the MnOx/SiO2 catalyst could be reused at least 5 times for selective cyclohexene oxidation with a negligible loss in its catalytic performance, indicating the excellent stability of shape-controlled metal nanocatalysts in organic synthesis under economically viable and mild conditions. Shape-controlled MnOx/SiO2 nanocatalyst shows an excellent catalytic activity and a high selectivity to allylic products in the oxidation of cyclohexene under mild conditions

A family of stable anticancer gold(III)-based therapeutic complexes containing cyclometalated triphenylphosphine sulfide ligands have been prepared. The anticancer properties of the newly developed complexes [AuCl2{κ2-2-C6H4P(S)Ph2}] (1), [Au(κ2-S2CNEt2){κ2-2-C6H4P(S)Ph2}]PF6 (2), [AuCl(dppe){κC-2-C6H4P(S)Ph2}]Cl (3), and [Au(dppe){κ2-2-C6H4P(S)Ph2}][PF6]2 (4) were investigated toward five human cancer cell lines [cervical (HeLa), lung (A549), prostate (PC3), fibrosarcoma (HT1080), and breast (MDA-MB-231)]. In vitro cytotoxicity studies revealed that compounds 2-4 displayed potent cell growth inhibition (IC50 values in the range of 0.17-2.50 μM), comparable to, or better than, clinically used cisplatin (0.63-6.35 μM). Preliminary mechanistic studies using HeLa cells indicate that the cytotoxic effects of the compounds involve apoptosis induction through ROS accumulation. Compound 2 also demonstrated significant inhibition of endothelial cell migration and tube formation in the angiogenesis process. Evaluation of the in vivo antitumor activity of compound 2 in nude mice bearing cervical cancer cell (HeLa) xenografts indicated significant tumor growth inhibition (55%) with 1 mg/kg dose (every 3 days) compared with the same dose of cisplatin (28%). These results demonstrate the potential of gold(III) complexes containing cyclometalated triphenylphosphine sulfide ligands as novel metal-based anticancer agents.

Tailored synthesis of heterostructures for low temperature (sub 200 °C) CO2 sensing continues to be a challenging task. The present study demonstrates CO2 sensing characteristics of CaO-ZnO heterostructures achieved by zinc hydroxide carbonate (Zn5(CO3)2(OH)6) conversion to ZnO using Ca(OH)2 at 50 °C. Control samples namely, Zn5(CO3)2(OH)6, Ca(OH)2, ZnO, and CaO integrated microsensors exhibited low sensitivity towards CO2 gas. However, CaO-ZnO heterostructures demonstrated significant sensitivity (26 to 91%) at 150 °C for gas concentration ranging from 100 to 10000 ppm, respectively. In this study, zinc hydroxide carbonate sensitized with 25 wt% Ca(OH)2 to form CaO-ZnO heterostructures (25CaZMS) displayed a promising sensitivity (77%) and selectivity (98%) towards 500 ppm CO2 gas. Moreover, the selectivity studies were conducted in the presence of 10 commonly found gases and their sensing performance was compared against CO2 gas in dry and humid conditions. The developed CaO-ZnO sensor exhibited faster kinetics in comparison to the control samples. Improved sensing performance observed here is attributed to the low-temperature synthesis route which resulted in a large number of active pores and high surface area morphology. Additionally, the high CO2 adsorption capacity of CaO combined with compatible n-type semiconductors in forming highly dynamic nano-interfaced heterostructure is a promising step towards developing a precise CO2 gas microsensor.

The ability of the multidentate nucleobases, adenine and thymine, to coordinate polyoxometalate and metal ions leading to the formation of self-assembled nanostructures and their strong cytotoxicity toward cancer cell lines have been demonstrated. A unique synthetic approach is developed to make a series of functional nanoscale hybrid materials consisting of nucleobases (adenine and thymine) and phosphomolybdic acid (PMA) through solid state chemical reaction and self-assembly process. Adenine was protonated through its ring nitrogen, while the ketone group in thymine was protonated during the addition of PMA to these nucleobases. The self-assembled nanostructures formed as a result of the electrostatic interaction between the protonated nucleobases and polyanionic PMA. To promote the base pairing between the nucleobases, chloroaurate ions and silver ions were added to each PMA/adenine and PMA/thymine nanostructures. The complexation between the nucleobases and the added metal ions was found to drive the formation of subsequent self-assembled nanostructures. All the materials were screened for their anticancer activity against breast (MDAMB-231) and prostate (PC-3) cancer cells, and non-cancerous keratinocyte cells HaCaT. PMA/adenine/[AuCl4]- and PMA/thymine/Ag+ nanostructures were found to have strong anti-cancer activity, while PMA/adenine/Ag+, PMA/thymine/[AuCl4]-, and PMA/pdenine, PMA/thymine nanostructures did not exhibit such activity. The unique redox properties of these materials and the self-assembly of the PMA and metal ions were the major factors responsible for the cytotoxicity. This unique approach of making functional nanomaterials incorporate the nucleobase, PMA and metal ions using solid state self-assembly and their anti-cancer applications are considered to be an effective approach for the development of inorganic nucleoside analogue bio-pharmaceutical agents.

Tetrahydrofurfuryl alcohol (THFAL) is a green solvent as well as a significant platform chemical which can be obtained from biomass derived furfural. In this study, new palladium exchanged vanadium incorporated supported heteropoly molybdate (PdMPAV2) catalysts were synthesized using a simple wet impregnation method and studied for selective hydrogenation of furfural. Six different catalysts were investigated: PdMPAV2/Al2O3, PdMPAV2/TiO2, PdMPAV2/SiO2, PdMPAV2/ZrO2, PdMPAV2/Nb2O5 and Pd/Al2O3. Of the catalysts studied the PdMPAV2/Al2O3 catalyst was able to achieve the highest selectivity of THFAL (95%) under moderate reaction conditions (150 °C, 2.5 MPa, 6 h) using isopropanol as a solvent and the weight percentage of palladium is only 0.5% which is the least among all the previously reported catalysts. The other catalysts investigated achieved yields of 50–75% under the same reaction conditions. The higher selectivity obtained using the alumina supported catalyst was explained using a range of physicochemical methods: XRD, temperature programmed reduction (H2-TPR), CO pulse chemisorption, BET surface area analysis and SEM. The H2-TPR results showed that PdMPAV2/Al2O3 contained a significant amount of Pd that was reduced at the lowest temperature (∼100 °C) observed for all the materials investigated, which indicated that this catalyst most likely contained a significantly greater amount of more highly dispersed/higher surface area Pd than the other catalysts investigated which is also supported by CO pulse chemisorption results. XPS results supported the presence of Pd(0) which is stabilized by a heteropoly acid framework, and TEM and CO chemisorption results illuminated the fact that the well dispersed and smaller palladium cluster is one of the crucial factors for the better activity of PdMPAV2/Al2O3. The effects of the variation of temperature, pressure, time and catalyst concentration were investigated for the best performing catalyst (PdMPAV2/Al2O3).

Presence of various types of micro-pollutants in domestic, industrial and municipal wastewater and landfill leachates are hazardous for living organisms. Thus, industries need to follow stringent requirements for discharging the chemicals in aquatic system. Organic pollutants, including dyes, hormones, phenols, pharmaceuticals, aromatic compounds, dyes, herbicides, pesticides, bromine containing retardants, industrial by-products, domestic products, sterilisers, and antiseptics, are referred as xenobiotic organic compounds (XOCs). Traditional treatment techniques used for organic pollutant removal is not sufficient. The porous carbonaceous structure of granular (GAC) and powdered (PAC) activate carbon can adsorb targeted pollutants from water. The surface area of activated carbon can be varied from (500–1500 m2g−1). The first part of the chapter illustrated the basic mechanism for adsorptive removal of contaminants over powdered and granular activated carbon (PAC or GAC). Now a days, adsorption onto activated carbon is integrated with biological process for treating industrial effluents. Adsorption integrated with biological treatment of waste water can be carried out using powdered activated carbon membrane bioreactor (PAC-MBR) and biological activated carbon reactor (BAC). The fundamentals of using activated carbon adsorption process integrated with biological treatment is discussed in the subsequent section of the chapter.

Selective laser melting printed metal lattice structures functionalised using zeolites have been shown as a promising new generation of catalysts. The unprecedented catalytic activity can be explained by metal migration (most likely chromium) from the support into the zeolite phase making it a promising candidate for endothermic fuels for high-speed flight vehicles.

Increasingly explored over the last decade, gold complexes have shown great promise in the field of cancer therapeutics. A major obstacle to their clinical progression has been their lack of in vivo stability, particularly for gold(III) complexes, which often undergo a facile reduction in the presence of biomolecules such as glutathione. Herein, we report a new class of promising anticancer gold(I)–gold(III) complexes with the general formula [XAuI(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuIIIX] [X = Cl (1), Br (2), NO3 (3)] which feature two gold atoms in different oxidation states (I and III) in a single molecule. Interestingly, gold(I)–gold(III) complexes (1–3) are stable against glutathione reduction under physiological-like conditions. In addition, complexes 1–3 exhibit significant cytotoxicity (276-fold greater than cisplatin) toward the tested cancer cells compared to the noncancerous cells. Moreover, the gold(I)–gold(III) complexes do not interact with DNA-like cisplatin but target cellular thioredoxin reductase, an enzyme linked to the development of cisplatin drug resistance. Complexes 1–3 also showed potential to inhibit cancer and endothelial cell migration, as well as tube formation during angiogenesis. In vivo studies in a murine HeLa xenograft model further showed the gold compounds may inhibit tumor growth on par clinically used cisplatin, supporting the significant potential this new compound class has for further development as cancer therapeutic.

The elemental mercury (Hg 0 ) vapor removal ability of α-MnO 2 nanotubes (NTs), nanorods (NRs) and nanowires (NWs) was evaluated in simulated natural gas mixtures. It was shown that NTs exhibited superior efficiency (~100%) at the temperature range of interest (25–100 °C). The Hg 0 breakthrough (corresponding to 99.5% Hg 0 removal efficiency) at ambient conditions and Hg 0 in = 870 μg∙m −3 , occurred after 48 h, reflecting a Hg 0 uptake of >10 mg∙g −1 (1 wt%). Most importantly, the developed nanosorbent was repeatedly, sufficiently regenerated at the relatively low temperature of 250 °C in a series of seven successive sorption-desorption tests, maintaining its capacity to remove all incoming Hg 0 in in each cycle. Interestingly, kinetic studies showed that at least 85% of total adhered Hg 0 could be recovered within the first hour of a 3-h regeneration process. Moreover, the presence of CO 2 and H 2 S did not affect its activity. The thermogravimetric analysis indicated significantly higher dehydration for NTs due to the loss of bound water inside its tunnels, likely indicating the presence of abundant surface adsorbed oxygen species which are believed to facilitate Hg 0 adsorption. This was also confirmed by X-ray spectroscopy, possibly explaining the enhanced activity of NTs.

The rational design of binuclear Au(I)–Au(I), Au(II)–Au(II), and Au(I)–Au(III) complexes requires an understanding of how the redox states interconvert. Herein, the electrochemical interconversion of the three oxidation states I, II, and III is reported on the voltammetric (cyclic and rotating disk electrode) time scales for binuclear gold complexes containing C6F4PPh2 as a ligand, to demonstrate for the first time formation of a binuclear Au(II)–Au(II) from a Au(I)–Au(III) complex. Results are supported by bulk electrolysis and coulometry with reaction products being identified by 31P NMR and UV–vis spectroscopy. All electrochemical processes involve an overall two-electron charge-transfer process with no one-electron intermediate being detected. Importantly, the kinetically rather than thermodynamically favored isomer [Au2IIX2(μ-2-C6F4PPh2)2] is formed on redox cycling of [XAuI(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuIIIX] (X = Cl, ONO2). Finally, a mechanism is proposed to explain the simultaneous change of coor...

In this report, the gas sensing performance of zinc titanate (ZnTiO3) nanoarrays (NAs) synthesized by coating hydrothermally formed zinc oxide (ZnO) NAs with TiO2 using low-temperature chemical vapor deposition is presented. By controlling the annealing temperature, diffusion of ZnO into TiO2 forms a mixed oxide of ZnTiO3 NAs. The uniformity and the electrical properties of ZnTiO3 NAs made them ideal for light-activated acetone gas sensing applications for which such materials are not well studied. The acetone sensing performance of the ZnTiO3 NAs is tested by biasing the sensor with voltages from 0.1 to 9 V dc in an amperometric mode. An increase in the applied bias was found to increase the sensitivity of the device toward acetone under photoinduced and nonphotoinduced (dark) conditions. When illuminated with 365 nm UV light, the sensitivity was observed to increase by 3.4 times toward 12.5 ppm acetone at 350 °C with an applied bias of 9 V, as compared to dark conditions. The sensor was also observed to have significantly reduced the adsorption time, desorption time, and limit of detection (LoD) when excited by the light source. For example, LoD of the sensor in the dark and under UV light at 350 °C with a 9 V bias is found to be 80 and 10 ppb, respectively. The described approach also enabled acetone sensing at an operating temperature down to 45 °C with a repeatability of >99% and a LoD of 90 ppb when operated under light, thus indicating that the ZnTiO3 NAs are a promising material for low concentration acetone gas sensing applications.

In this study, we developed a novel method of integrating the well-accepted cold vapor technique with gold nanostructured based quartz crystal microbalance (QCM) devices to selectively detect mercury ions (Hg2+). This method allows for the conversion of aqueous mercury ions into elemental mercury (Hg°) vapor form and thereon use the highly sensitive QCM based mercury vapor sensors to detect the evolved mercury. The method involves reducing mercury chloride (HgCl2) in contaminated water by mixing it with a 2% tin chloride (SnCl2) solution in order to evolve Hg° vapor from the liquid mixture. The selectivity and sensitivity performance of each gold nanostructure, namely, the control Au thin film (Au-ctrl), Au-nanospheres (Au-NS) and Au-nanourchins (Au-NU), towards mercury vapor was evaluated. It was found that Au-NS and Au-NU sensors displayed up to 79% and 243% higher response magnitudes than the Au-ctrl sensor for various concentrations of HgCl2, respectively. All three sensors exhibited repeatable sensing performance when reporting the concentrations from 5 sensing events involving 500 ppb HgCl2 solution with Au-ctrl, Au-NS and Au-NU having the coefficient of variance (CoV) values of ˜5.7, 2.9 and 3.8%, respectively. Moreover, the sensors were observed to operate in the linear region with the mercury ion concentration range calibrated and tested. Importantly, the sensors showed no cross-interference effects when tested toward Hg2+ ions with and without the presence of other metal ions such as lead, cadmium, manganese, iron, and zinc. The results indicate that the CV-QCM technique developed is feasible to be potentially used in real-world mercury monitoring applications.

The sustainable synthesis of high-quality graphene sheets is one of the hottest and most inspiring topics in the fields of science and engineering. While the graphene oxide (GO) chemical reduction ...

The beneficiation of ferruginous rare earth bearing ores derived from lateritic deposits by conventional mineral dressing processes is usually difficult due to characteristics of these ores such as fine grain size, complex texture and similar physical characteristics between rare earth minerals and iron oxide gangue. The removal of iron oxides would offer significant advantages with respect to downstream rare earth mineral processing. The purpose of this study was to demonstrate at bench scale the feasibility of magnetically separating iron oxides from a ferruginous lateritic rare earth ore after the ore had been subjected to reduction roasting to convert feebly magnetic iron (III) oxides to magnetite. The effects of magnetic field strength and feed top size on the efficiency of low intensity magnetic separation (LIMS) was explored through rougher magnetic separation tests using a Davis tube tester and chemical and mineralogical analysis of the rougher magnetic concentrates and tails was performed. Magnetic separation was successful in removing iron (as magnetite) to the concentrate at a minimum field strength of 0.2 T; this was however non-selective, with significant amounts of rare earths reporting to the magnetic fraction. The rare earth enriched tails showed decreased grade and recovery and this was due to a number of factors including insufficient liberation, presence of iron oxide coatings on mineral surfaces and heteroflocculation. The findings of this study provided insight towards the potential optimisation and viability of the proposed process of magnetising roasting and low intensity magnetic separation as a means to beneficiate ferruginous lateritic rare earth ores.

The last decade has witnessed tremendous advances in the design of anticancer gold complexes containing tertiary phosphines, a class of ligands that have significantly contributed to the development of metal complexes owing to their stabilizing effect. The promising in vitro antiproliferative properties of the phosphine-containing organogold compound auranofin [1-(thio-kS)-2,3,4,6-tetra-O-acetyl-β- d -glucopyranose](triethylphosphine-kP)gold(I), originally used to treat rheumatoid arthritis, inspired the extensive application of monodentate phosphines in the development of anticancer gold complexes. Meanwhile, the use of diphosphine ligands promoted advances in the preparation of chelated gold complexes as well as mixed-metal and mixed-ligand complexes that have superior anticancer activity. The present report summarizes the current state of knowledge of diphosphine ligands in the development of anticancer gold complexes, and explores challenges and opportunities in designing gold-containing mixed-metal and mixed-ligand complexes that have anticancer action.

Bimetallic nanoparticles (BMNPs) have received considerable attention due to their distinctive properties when compared to the corresponding monometallic NPs and their bulk counterpart. In this report, the formation of gold@silver core-shell nanoparticles (Au@AgCSNPs) was achieved via a one-pot synthetic approach after mixing 1:1 M solutions of Au and Ag ions. L-cysteine was used as reducing as well as capping agent for preparing Au@AgCSNPs. Ultraviolet-visible (UV-Vis) spectroscopy was employed for surface plasmon study while Fourier-transform infrared (FTIR) spectroscopy gave insights for interaction of NPs with specific functionality of the capping material. Surface morphology of the fabricated Au@AgCSNPs, probed by atomic force microscopy (AFM), indicated an average height of nanoparticles around 43 ± 3 nm and their crystallinity were confirmed via powder X-ray diffraction (PXRD) study. Significantly, the as synthesized Au@AgCSBMNPs were fabricated onto the conductive surface of glassy carbon electrode (GCE), stabilized with nafion, and then utilized as an extremely sensitive/greatly selective sensor for voltammetric detection of Hg2+. The developed sensor responded linearly to Hg2+ between 0.001 and 19 ppb with limit of detection (LOD) as low as 0.0001 ppb (0.1 ppt). Finally, the sensor was effectively applied for Hg2+ detection in different groundwater samples and is workable at concentrations undetectable by several sensing tools.

Selective reduction of various nitroarenes to amines was achieved up to 93% under autoclave condition in isopropanol using catalytic amount of palladium oxide/copper oxide (PdO/CuO) nanoparticles (...

A series of alkynylgold(I) phosphine complexes containing methoxy-substituted cinnamide moieties (3a-3c and 4a-4c) have been synthesized and characterized. All of the synthesized complexes were evaluated for their cytotoxicity against three human cancer cell lines A549 (lung), D24 (melanoma), and HT1080 (fibrosarcoma) and the human embryonic kidney 293 cell line (Hek293T) as a proxy model for noncancer cells. Most of the synthesized compounds showed antiproliferative activity against cancer cell lines at low micromolar concentrations. Among these, complex 3c showed a broad spectrum of anticancer activity with IC50 values in the range of 1.53-6.05 μM against all tested cancer lines. Complex 3c possessed 20 times higher cytotoxicity than the reference drug cisplatin against D24 melanoma cells and showed significant anticancer activity in 3D spheroidal models of melanoma cells. Mechanistic investigations of 3c activity indicate thioredoxin reductase inhibition through steric and hydrogen-bonding interactions, followed by the induction of oxidative stress and a mitochondrial pathway of cell death. Compound 3c also showed significant antiangiogenic properties in a transgenic zebrafish Tg(fli1a:EGFP) in vivo model.

Synergistic composite metal oxides are proven to be impressive materials due to their multi-functionalities across various catalytic applications. In a composite metal oxide, the interfacial chemistry between the components could provide exceptional redox and catalytic properties. In the present manuscript, the fundamental focus is devoted to investigating the interactions between active metal oxides at their interfaces and the catalytic activities towards diesel soot and CO oxidation. A series of flower-like microspheres namely, CeO2, 10%Mn3O4/CeO2, 20%Mn3O4/CeO2, and 40%Mn3O4/CeO2 catalysts were synthesized, where the effect of different Mn3O4 loadings towards soot combustion and CO oxidation were investigated. The characteristic 50% conversion temperature (T50) of catalytic soot oxidation under loose and tight contact conditions for CeO2 microspheres are 502 and 484 °C, respectively. After the integration of Mn3O4 and CeO2, the T50 values were decreased with the lowest values observed for the 20%Mn3O4/CeO2 microspheres (381 and 350 °C). Similarly, 20%Mn3O4/CeO2 microspheres showed T50 value at 103 °C for CO oxidation when compared to pure CeO2 microspheres (216 °C) and Mn3O4 nanoparticles (356 °C). Activation energy values were decreased when the Mn3O4/CeO2 composite used in soot and CO oxidation. The high catalytic activity can be attributed to the strong synergistic interactions between CeO2 and Mn3O4, variable oxidation states, the amount of readily available surface redox active sites and oxygen vacancies. The possible interfacial interaction between CeO2 and Mn3O4 can be exploited to exhibit enhanced surface structural, and redox properties when compared to the pure counterparts. Post-catalytic oxidation analysis confirms the high stability of the Mn3O4/CeO2 composite. The present study points out the vital role of interfacial interactions in composite metal oxides for improving the surface and redox properties, which are important for the development of highly efficient soot and CO oxidation catalysts.

Gold nanoparticles are inert for the human body, and therefore, they have been functionalized to provide them with antibacterial properties. Here, elongated tetrahexahedral (ETHH) Au nanoparticles were synthesized, characterized, and functionalized with lipoic acid (LA), a natural antioxidant with a terminal carboxylic acid and a dithiolane ring, to generate ETHH-LA Au nanoparticles. The antioxidant activity of Au nanoparticles was investigated in vitro, showing that LA enhances the 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging and Fe

TiO2 nanorods-supported MnOx, FeOx, CrOx, and MnOx-FeOx-CrOx catalysts have been prepared by a deposition-precipitation method, with the aim of investigating the combination of ternary metal oxides effect on elemental mercury (Hg0) removal. The TiO2 nanorods-supported MnOx-FeOx-CrOx catalyst manifested the superior Hg0 removal efficiency (∼80-83%) at low temperatures (100–200 °C) in the presence of O2. The addition of NO promoted the Hg0 removal efficiency under the same reaction conditions. Further, SEM, HRTEM, XRD, BET surface area, and XPS characterization were carried out to explore the physicochemical properties of the catalysts. It was found that the integration of three active metal oxides contributed to the enrichment of active sites and the surface adsorbed oxygen species, thereby improving the catalytic activity. Additionally, both the large surface area and high crystallization of the obtained TiO2 nanorods resulted in uniform dispersion of the manganese-iron-chromium mixed metal oxide nanoparticles and a high activity. Further, XPS data of spent MnOx-FeOx-CrOx/TiO2 catalyst indicated that the presence of Mn4+, Cr6+, and Fe3+ could promote Hg0 oxidation due to the strong synergistic interaction between the TiO2 nanorods-incorporated MnOx, FeOx, and CrOx nanoparticles.

The experimental solubility data of l-glutamic acid in pure water, formic acid, methanol, 1-propanol, 2-propanol, acetonitrile, and binary mixtures (formic acid + water, methanol + water, 2-propanol + water, acetonitrile + water) with different compositions were carried out at temperatures ranging from (283.15 to 328.15) K by the static analytic method. The solubility measurements showed that formic acid and its aqueous mixtures recorded a higher solubility than methanol + water, 2-propanol + water, and acetonitrile + water for the same composition at each temperature. Moreover, except formic acid the addition of methanol, 2-propanol, and acetonitrile to its aqueous mixtures resulted in the decrease in solubility of l-glutamic acid. The experimental data was fitted using different thermodynamic models such as the Buchowski-Ksiazczak equation, the Van't Hoff equation, the modified Apelblat equation, and the NRTL model, and the optimum values of the regressed parameters were obtained. The modified Apelblat equation, Buchowski-Ksiazczak equation, and NRTL activity coefficient model were fitted to the pure solvents solubility data, while the modified Apelblat, modified Apelblat-Jouyban-Acree, and NRTL models were used for the binary solvent systems. The results demonstrated formic acid as a cosolvent in the dissolution of l-glutamic acid in formic acid + water binary mixtures, while others exhibited an antisolvent effect on the solubilization of l-glutamic acid in their respective aqueous mixtures.

Cleavage of the bromide bridges in [Pd2(μ-Br)2{κ2(Sn,As)-2-MeBrSnC6F4AsPh2}2] (1) by diphosphine ligands gave the mono- and dinuclear palladacycles [Pd(L)Br{κ2(Sn,As)-2-MeBrSnC6F4AsPh2}] [L = dppe (2) dppm (3), ortho-dppBz (4)] and [Pd2Br2(para-dppBz){κ2(Sn,As)-2-MeBrSnC6F4AsPh2}2] (5). The interactions of these complexes with DNA (CT-DNA) and proteins (human serum albumin) were studied by UV-Vis and fluorescence spectroscopy, respectively. The results confirmed the interaction of these palladium complexes with CT-DNA through groove binding, and their strong binding affinity to HSA. The anti-proliferative activities of complexes 1-5 were tested against four human cancer cell lines (HeLa, A549, PC-3, and HT1080) and normal keratinocytes (HaCaT). Among the series, the palladium(ii) complex containing the 1,2-bis(diphenylphosphino)benzene ligand (4) showed the highest cytotoxicity against HeLa, PC-3 and HT1080 cells, with IC50 values of 0.25 ± 0.08, 0.85 ± 0.11, and 0.66 ± 0.15 μM, respectively. Interestingly, compound 4 exhibited lower cytotoxic activity toward normal HaCaT cells (IC50 = 4.65 ± 0.16 μM). Additionally, this complex exhibited lower toxicity and better anti-cancer activity than cisplatin. Further mechanistic studies, including Hoechst staining and flow cytometry, confirmed that complex 4 induced G2/M phase cell cycle arrest and apoptotic cell death in HeLa cells.

Atomically thin two-dimensional (2D) nanosheets of metal oxides with structural anisotropy, rich surface chemistry and unique electronic structures are technologically intriguing. Importantly their chemical versatility makes them different from their counterparts and potential candidates for number of applications, specifically in the field of energy. This review article will summarize the recent progress in the synthesis of atomically thin 2D metal oxides and their applications for energy storage. It will first explain the structural fundamentals at atomic level thickness and change in surface chemistry due to defective structure and/or unsatisfied surface atoms. Further, it will highlight how different synthesis routes bring variety of 2D materials with tuneable electronic structures. In progress, it will describe the advantages of atomically thin materials over their bulk equals for applications in energy storage devices such as batteries and supercapacitors. Finally, conclusive remarks will be listed with future perspectives towards designing heterostructured metal oxides in 2D nanosheets to overcome their limitations for various energy storage applications.

The hydrophobic ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF6] forms nanostructures with negatively charged plasmid DNA through electrostatic interactions. The formation of plasmid DNA/IL nanostructures was confirmed by measuring the zeta potential of plasmid DNA as well as plasmid DNA/IL nanostructures. The zeta potential of the nanostructures was positive, although plasmid DNA is negatively charged. The positive zeta potential is due to the complexation between plasmid DNA and positively charged ionic liquid [Bmim][PF6]. The ability of ionic liquid [Bmim][PF6] to protect plasmid DNA against ultrasonic shear stress was also investigated using an agarose gel electrophoretic assay and showed that ionic liquid stabilizes plasmid DNA against ultrasonication. The plasmid DNA and plasmid DNA/IL nanostructures were subjected to ultrasonic shear stress for different time periods and the biological functionality of pristine plasmid DNA (i.e., expression of the eGFP gene) as well as the self-assembled nanostructures was investigated in vitro using three different cell lines, COS7, HEK293 and HeLa. Ionic liquid [Bmim][PF6] protected the plasmid DNA against ultrasonic shear stress and also enhanced gene transfection efficiency in vitro. Furthermore, the cytotoxicity of ionic liquid [Bmim][PF6] was assayed in vitro using all three cell lines and the toxicity was very low. Therefore, the ionic liquid [Bmim][PF6] stabilizes plasmid DNA against ultrasonic shear stress and also enhances its in vitro delivery efficiency.

Hydrotalcite-derived (HT-derived) oxide catalysts were synthesised from hydrotalcite-like (HT-like) materials prepared by co-precipitation method (Cu-Al, Cu-Fe, Mg-Al, Mg-Fe, Ni-Fe and Ni-Al) followed by calcination and their catalytic activity was studied for oxidative amidation of carboxylic acids and substituted benzaldehydes with N,N-dimethylformamide (DMF). Catalyst screening was done using benzoic acid and DMF as a model reaction. Subsequently, we have optimised the reaction with different reaction parameters, catalyst loading, temperatures and oxidants. Cu-Fe HT-derived oxide catalyst showed excellent activity towards oxidative amidation using TBHP as an oxidant at 80 °C in 10 h. The fresh and spent catalysts were thoroughly characterised by different analytical techniques; XRD, SEM, HRTEM, TPD, N2 adsorption-desorption isotherm and XPS. Moreover, the catalyst was easily separated by simple filtration and reused up to four cycles without significant loss in catalytic activity.

Silicon-based impurities are ubiquitous in natural graphite. However, their role as a contaminant in exfoliated graphene and their influence on devices have been overlooked. Herein atomic resolution microscopy is used to highlight the existence of silicon-based contamination on various solution-processed graphene. We found these impurities are extremely persistent and thus utilising high purity graphite as a precursor is the only route to produce silicon-free graphene. These impurities are found to hamper the effective utilisation of graphene in whereby surface area is of paramount importance. When non-contaminated graphene is used to fabricate supercapacitor microelectrodes, a capacitance value closest to the predicted theoretical capacitance for graphene is obtained. We also demonstrate a versatile humidity sensor made from pure graphene oxide which achieves the highest sensitivity and the lowest limit of detection ever reported. Our findings constitute a vital milestone to achieve commercially viable and high performance graphene-based devices., Silicon-based contaminants are ubiquitous in natural graphite, and they are thus expected to be present in exfoliated graphene. Here, the authors show that such impurities play a non-negligible role in graphene-based devices, and use high-purity parent graphite to boost the performance of graphene sensors and supercapacitor microelectrodes.

Online mass spectrometry is a widely used technique in tracking composition changes of gas mixture during the reaction. This paper reports a quantification analysis method of gas mixtures detected by an online mass spectrometry. In this analysis, a mass spectrum correction coefficient matrix is generated based on the calibration of mass spectrometry intensities of premixed calibration gas mixtures, and then the concentrations of gas components are calculated from this matrix by subtracting the interferences of other components with overlapped peaks. The accuracy of obtained results were verified by online gas chromatography in the meanwhile. The detailed error analysis was supplied in a separate supplement document. This method can be applied on the online detection of gas phase reactions with promising advantages to analysis of online gas chromatography, which is suitable for analysis of spectra overlaps (a given m/z signal contributed from two or multiple components) and kinetic studies.

Using colloidal lithography, gold honeycomb (AuHC) monolayer crystals with various degree of porosity were formed on quartz crystal microbalance (QCM) electrodes thus enabling the experimental determination of the important role that surface parameters (pore size, surface area etc.) play in the sensing of gaseous species such as mercury vapor. The pore size was controlled through altering the O2 plasma etching periods of the close-packed monodispersed polystyrene colloidal crystal templates. It was found that the reduced pore size (or increased surface area) of AuHC structures enhanced the sensitivity of the QCMs toward mercury vapor adsorption, however the enhancement could not be correlated to the surface area increase alone. For example, the QCM containing AuHC structures which had been etched for 12 min (AuHC12 min) had similar Au mass and surface area as the control QCM with its continuous thin film of Au (Au-Ctrl), yet exhibited around twice the response magnitude when exposed toward elemental mercury (Hg°) vapor at 30 °C. The increased response magnitude could only be explained by the increased number of available active sites undergoing Hg° sorption which are present around the edges of the honeycomb pores. The QCM data showed that the number density of these active sites increased with increasing plasma etching periods as evidenced by the AuHC12 min QCM showing 7.4 times higher response magnitude toward Hg° vapor over the AuHC0 min based QCM when operated at 30 °C. Furthermore, the selectivity of the AuHC12 min based QCM was shown to be operating temperature dependent when undergoing cross-interference tests against common industrial gases such as humidity, ammonia, mercaptans, ketones and aldehydes, where improved selectivity was observed at elevated operating temperature of 75 °C.

The design and synthesis of surface engineered functional inorganic nanomaterials for environmental applications is a long-standing goal of biomimetic research. Further developments in using nanomaterials for environmental engineering applications rely upon their surface modification, efficient sensing, stability under harsh conditions, biocompatibility, and less adverse environmental impact. Therefore, in this chapter, we review the amino acid functionalized inorganic nanomaterials, class of emerging materials that can address the afore-mentioned challenges to realize their environmental applications. These nanomaterials structurally mimic the characteristics of natural enzymes chirality, molecular recognition catalytic properties as well as possess the inherent electronic, optical, and catalytic properties of nanoparticles.

Catalytic hydrogenation of 1,3-butadiene to produce selectively 1-butene has considerable importance in the hydrocarbon industry and presents a significant challenge in tuning the catalyst selectivity towards 1-butene, understanding the reaction and kinetic mechanism. Selective hydrogenation over metal oxide-supported palladium catalysts is considered as a standard process; however, selectivity towards 1-butene is achieved by alloying palladium with other metals that facilitate the desorption of adsorbed alkene intermediate and limit further hydrogenation to form butane. In this book chapter, we summarize the current state of the art and perception of various factors that control the catalyst activity, adsorption of intermediates on the active sites and eventually the selectivity. In particular, we present a concise description of active metal dispersion, structure sensitivity, influence of support, promoter and their role in governing the selectivity of 1-butene from 1,3-butadiene hydrogenation. Then, this chapter highlights the detailed analysis of reaction kinetics and reaction mechanisms that are proposed clearly. Finally, a brief overview of the theoretical investigations for 1,3-butadiene hydrogenation using density functional theory (DFT) calculations has also been discussed for a variety of catalysts and followed discussion about summary and future outlook.

Australia has an advantage of having an abundant source of solar- and wind-based renewable energy. It can be utilized for renewable hydrogen production via liquid ammonia (NH3) pathway. Countries importing renewable ammonia can decompose it back to pure hydrogen using CSIRO (Commonwealth Scientific and Industrial Research Organization) metal membrane technology. The membrane separates ultrahigh pure hydrogen from ammonia while blocking all other gases. Re-cracked hydrogen can be used for fuel cell vehicles and other energy applications. The assessment of the economic viability of the abovementioned process chain requires a techno-economic evaluation (TEE) that involves process simulation, mass and energy balances, plant sizing, capital and operating cost estimations, and cash-flow and sensitivity analyses. This chapter presents the TEE methodology for a hydrogen energy system and it can be used in assessing engineering, research and development impact, scale-up, and the feasibility of the production system.

The demand for water supply is expected to be raised significantly in forthcoming decades. Production of reusable water from industrial and domestic wastewater is a feasible, cost effective and significant positive benefit to the environment. In the present study, the domestic rice gruel wastewater (RGW) was treated with aqueous methanol coagulation integrated aerobic membrane bioreactor (AMBR). Initially, the RGW which is at room temperature was treated with spiral wound hydrophilized - ultrafiltration (HF – UF) 5 kDa membrane module to determine the removal efficiency. Furthermore, the RGW was pre-treated with various coagulants such as methanol, ethanol and HCl. The obtained pre-treated RGW was subjected to the HF – UF 5 kDa side stream AMBR for production of reusable water. The experiments were conducted to determine the turbidity, conductivity, total dissolved solids (TDS) and chemical oxygen demand (COD) were found to be 96 %, 91 %, 91 % and 94.6 %. The overall process was feasible, compact, environmental free, cost effective, eco-friendly.

Chalcopyrite (CuFeS2) passivation during hydrometallurgical copper extraction is attributed to multiple competing mechanisms that are still not completely understood. Here we have studied the interfacial solution chemistry in situ at polarised chalcopyrite and chalcocite, using scanning electrochemical microscopy (SECM). It was observed that the copper species detected at an ultramicroelectrode (UME) positioned at the mineral:solution interface vary between the two minerals, and are dependent upon both the potential of the mineral and the polarisation time. Cu species formed in the presence of sulfide, derived from incomplete oxidation of chalcopyrite, are observed on the UME tip positioned above chalcopyrite under conditions where passivation may occur, in contrast to Cu(II) in the presence of sulfate under conditions where leaching is facile. Only Cu(II) in the presence of sulfate is observed at the interface of chalcocite. These observations via interfacial voltammetry provide experimental support to mechanistic studies on chalcopyrite leaching, and provide new information to complement previous in situ studies which have mostly focused on interfacial solids.

The development of new small molecules from known structural motifs through molecular hybridization is one of the trends in drug discovery. In this connection, we have combined the two pharmacophoric units (pyrimidine and thioindole) in a single entity via molecular hybridization strategy along with introduction of urea functionality at C2 position of pyrimidine to increase the efficiency of H-bonding interactions. Among the synthesized conjugates 12a-aa, compound 12k was found to exhibit significant IC50 values 5.85, 7.87, 6.41 and 10.43 μM against MDA-MB-231 (breast), HepG2 (liver), A549 (lung) and PC-3 (prostate) cancer cell lines, respectively. All these compounds were further evaluated for their inhibitory activities against VEGFR-2 protein. The results specified that among the tested compounds, 12d, 12e, 12k, 12l, 12p, 12q, 12t and 12u prominently suppressed VEGFR-2, with IC50 values of 310–920 nM in association to the positive control (210 nM). Angiogenesis inhibition was evident by tube formation assay in HUVECs and cell-invasion by transwell assay. The mechanism of cellular toxicity on MDA-MB-231 was found through depolarisation of mitochondrial membrane potential, increased ROS production and subsequent DNA damage resulting in apoptosis induction. Moreover, clonogenic and wound healing assays designated the inhibition of colony formation and cell migration by 12k in a dose-dependent manner. Molecular docking studies also shown that compound 12k capably intermingled with catalytically active residues GLU-885, ASP-1046 of the VEGFR-2 through hydrogen-bonding interactions.